I plan to Dremel it with the disc, the router type attachment is probably very slow, and file it to fit. The timer should arrive any day now, will report back how it goes/went.

Dremel works pretty well, so I'll continue along that avenue. Will show the result when done.

The "409" cutting wheel is a good choice. They are very thin and fairly easy to control when applied with light pressure to the surface. Wear a face shield and have no spectators as they are brittle and work best at high RPMs. They are smaller in diameter than the EZ409, so that may also be a good choice depending on where you are cutting on the grinder depending on the contour of the surface. The EX discs are more expensive but last a LOT longer. As noted, cut about .5mm inside the line and finish with a small file. It's always easier to take off more material- hard to put it back on (sort of like trimming a mustache).

I got the slightly thicker ones, needed two and was done pretty quickly. After figuring out the wiring, which took a bit as there are plenty of black wires and reds to choose from...

All that is left is adding some sealant, to keep fines from getting everywhere. minor oopsie...just noticed the timer only does full seconds, with a grinder as fast as the Major the difference between 5 and 6 seconds is quite large. We'll see...(perhaps the circuit can be adapted to do 9.99 sec in once scale, no clue what the board looks like but for a tenner I'll get one to rip apart)

http://www.youtube.com/watch?v=cBF7WnPkoxc




In case you needed some inspirstion or ideas.

LOL

Yeah I saw that mad machine and am sortof tempted to be able to put such a whacko machine on the new counter top in our new home in a year or two...guess i need to find another Major first as there is no way I can do without it for so long as the project takes...

For what it's worth, I did something similar many years ago: How to connect a Delta CTA to a grinder

That timer isn't cheap though.. It's lasted me over 10 years now of daily use. I can't say my ability to cut a square in a project box will win me any awards, but I sure didn't want to cut a hole in the grinder. That was more risk then I was willing to accept.

The timer still works, but the buttons to change the timer have gone.. I have bought a new one and they changed the buttons. The old one required you push fairly far in for it to register. The new timer requires a much lighter push. Currently on the old timer I have to push with a screwdriver and jiggle it and maybe if the stars are aligned it will register..

Cool project BTW. Looking forward to see how you finish up.

I found some more references, indeed I'm not the first nor the only one doing this. My main concern was to replace the large darkroom timer I have been using by a smaller integrated solution and I decided against an Arduino project as I did not feel like tinkering too much with programming etc.

it works, the timer should have had 0.1 sec divisions, but hey, 6 sec is close enough.



have to seal off the rim, and do some spray painting on the front to hide the almost mistaken location for the timer.....